The British drugs company GlaxoSmithKline is to open up the detailed data from its clinical trials to the scrutiny of scientists in a bid to help the discovery of new medicines and end the suspicions of critics that it has secrets to hide.

In a speech today to the Wellcome Trust in London, the chief executive, Andrew Witty, will say openness to the public and active collaboration with scientists and firms outside GSK are essential to finding new drugs to treat the diseases plaguing the world, from novel antibiotics to cures for malaria and tuberculosis.

He told the Guardian GSK had already done much to advance transparency in clinical research, including publishing a summary of every drug trial – whether a success or not – on its website.

"We've done an awful lot around this area but I think it's still fair to say that not everybody believes that everything is made public. Even things we do all the time we're criticised for not doing," he said. "People say we only publish positive trials. No, we publish everything. But the fact that people don't know or haven't yet accepted that we have this real commitment to transparency – we've got to keep working harder to get that message across."

GSK will set up an independent board which will assess requests from scientists to look at the anonymised patient data from the trials and grant access on merit through a secure website.

Witty accepted there could be attempts at fishing trips by anti-vaccination groups or critics of GSK drugs such as the antidepressant Seroxat, which was linked a decade ago to increased suicidal feelings in the young, amid accusations that the company had known and hidden the data years earlier.

Witty, who took over as CEO when the scandal had largely died down, said he was prepared to take the risk: "We know it's possible people will mix and match different data, come up with what we would regard as non-scientifically credible conclusions but, in a way, it's not our job to decide that. It's the job of society, the regulators, to make a decision about what's credible and what isn't credible as a scientific conclusion."

He said nothing would make him happier than to see outside scientists use the data to find new drugs. "While of course there is a risk of mischief, I think there is a much higher possibility of transforming the usefulness of this data on a much more positive set of agendas.

"There isn't a day goes by that me and the rest of the company aren't grateful for what patients offer to do in a clinical trial. They offer willingly to go through a process of experimentation. That's an extraordinary gift from individual men and women. At one very human level actually we should be finding ways to make that commitment as useful as it can possibly be for society."

Witty will also announce new initiatives in the hunt for cures for neglected tropical diseases, building on a strategy begun soon after he took over as CEO. GSK has now screened its entire pharmaceutical library of more than 2m compounds to find any that could inhibit tuberculosis, he will say. It has found 200 promising "hits" that the company will make available to researchers wanting to investigate further. GSK did the same for anti-malarial compounds in 2009, which has led to a number of research projects into potential new drugs.

An extra £5m funding to the Open Lab, which the company established at its Tres Cantos facility in Spain in 2010, will also be announced. Independent researchers with projects relating to developing world diseases are invited to use its facilities and collaborate with GSK scientists. There are 16 such projects under way.

Witty said he had tried to tackle the issues that people outside the drug industry cared about, such as transparency, access to medicines and prices, not through corporate social responsibility "but by fundamentally challenging the business model that we operated". That included allowing researchers to work on compounds over which GSK had patents in the hunt for cures for neglected tropical diseases. "Whatever tiny risk we took in that decision has more than paid off in terms of what it has led to, I think for people in Africa and people who suffer from these diseases."

Sir Mark Walport, director of the Wellcome Trust, is a keen advocate of transparency, calling particularly on scientists with public funding to make the results of their research freely and widely available. He was supportive of Witty's initiatives.

"In its commitment towards more openness and collaboration, GSK is setting an example of how the pharmaceutical industry must adapt to help drive forward medical advances. Real breakthroughs do not come out of nowhere, but are borne of scientists sharing their knowledge and learning from each other. GSK's moves are bold and innovative, a very positive sign of its commitment to tackle some of the greatest health challenges facing the world today," he said.